1. Field of the Invention
The present invention relates to a slim USB male connector with system grounding, and particularly to a slim USB male connector complying with A-type USB specifications with a hidden grounding portion for achieving system grounding
2. Description of the Prior Art
The Universal Serial Bus (USB) is an astonishingly useful way to connect large numbers of peripherals together. It is becoming increasingly important in today's electronics world. One of the reasons that USB was implemented was to replace existing serial and parallel ports on computers. USB has several advantages for this application.
First, it uses a much higher data transfer rate than many common serial data formats.
Second, it allows a large number of devices to be attached to a single host USB connector. Up to 127 devices can theoretically be used on a single USB port.
Third, it simplifies the connection to external devices. USB supports “plug and play” where the operator does not need to be heavily involved in the set-up process. When a device is connected to a host's USB bus, it is immediately recognized by the host, dynamically enumerated, and assigned an address by the host.
Reference is made to FIG. 1, which is a perspective view of A-type USB socket (a female connector) and an USB connector (a male connector). The A-type USB socket 70 and USB connector 90 follow A-type physical specifications for achieving electrical connection. The USB socket 70 is usually mounted on a PCB 80 of the host (not shown) grounded with the computer system. The USB socket 70 has a frame 72 and a mating board 76 mounted in the frame 72. The frame 72 is formed by stamping a metal board and formed with a plurality of elastic tongues 74 on a periphery of the frame 72. The mating board 76 is formed with an insulative material and mounted with four contacts 78. A receiving space 79 is formed between the mating board 76 and the frame 72. The USB connector 90 uses a four-wire cable interface 91. Two of the wires are used in a differential mode for both transmitting and receiving data, and the remaining two wires are power and ground. The source of the power to a USB device can come from the host or a hub. The USB connector 90 has a housing 92 made by stamping and formed with four cutouts 94 thereon, and a mating board 96 that is mounted in the housing 92 and disposed with four terminals 98 on an upper surface thereof. The housing 92 complies with USB-IF grounding requirements by grounding with the computers via the USB socket 70. When the USB connector 90 is inserted into the USB socket 70, the tongues 74 of the frame 72 of the USB socket 70 are clipped and wedged in the cutouts 94 of the housing 92. The four terminals 98 of the mating board 96 are respectively electrically connected with the contacts 78 of the mating board 76.
However, the metal housing 92 limits the size of the USB connector 90. When inserting the USB connector 90 into a stacked USB socket, it is crowded by the neighboring USB connector and is inconvenient. The slim design of the USB connector 90 is restricted by the housing 92 and the housing 92 becomes an obstacle to slim design.
Hence, an improved slim USB male connector is required to overcome the disadvantages of the prior art.